Specifications

Application Examples Softstart UK
10.7. Two Speed Motor
The LV-DS can be configured for control of dual speed Dahlander type motors, using a high speed contactor
(KM1), low speed contactor (KM2) and a star contactor (KM3).
NOTE
Pole Amplitude Modulated (PAM) motors alter the speed by effectively changing the stator
frequency using external winding configuration. Soft starters are not suitable for use with this type
of two-speed motor.
When the soft starter receives a high speed start signal, it closes the high speed contactor (KM1) and star
contactor (KM3), then controls the motor according to the primary motor settings.
When the soft starter receives a low speed start signal, it closes the low speed contactor (KM2). This closes
Input A and the LV-DS controls the motor according to the secondary motor settings.
08882.A
5
6
7
1
2
3
4
2/T1
4/T2
6/T3
E
T4
T5
T6
T1
T2
T3
A6
A4
A5
1/L1
3/L2
5/L3
24
22
21
KA1
KA2
KA1
KA2
KM3
KA1
KM2
KA2
KM1
KM2
KM3
KM1
KM3
KM1
KM3
KM2
S1
KM2
KM1
KA1
56
57
58
53
55
54
1
Control voltage
KA1
Remote start relay (low speed)
2
Remote control inputs
KA2
Remote start relay (high speed)
3
Relay outputs
KM1
Line contactor (high speed)
4
Three-phase supply
KM2
Line contactor (low speed)
5
Motor terminals
KM3
Star contactor (high speed)
6
Remote low speed start input
S1
Reset contact
7
Remote high speed start input
21, 22, 24
Relay output B
NOTE
Contactors KM2 and KM3 must be mechanically interlocked.
Parameter settings:
• Parameter 6D Input A Function
• Select 'Motor Set Select' - assigns Input A for Motor set selection.
• Set high speed performance characteristics using the primary motor settings.
• Set low speed performance characteristics using the secondary motor settings.
• Parameter 7D Relay B Function
• Select 'Trip' - assigns Trip function to Relay Output B
NOTE
If the LV-DS trips on supply frequency (parameter 16F Frequency) when the high-speed start
signal (7) is removed, modify the frequency protection settings.
56/64 710-15797-00A – LV-DS User Manual